Unloading mechanism for an automatic gun



y 1967 E. w. JAFWERT 3,319,525

UNLOADING MECHANISM FOR AN AUTOMATIC GUN Filed July 30, 1965 BY HAM wul/ A Tram/ m United States Patent Filed July 30, 1965, Ser. No. 476,tl80 Claims priority, application Sweden, Aug. 14, 1964, 9,884/ 64 3 Claims. (Cl. 8945) The present invention is related to an unloading mechanism for an automatic gun, in particular for an antiaircraft automatic gun, of the type having a non-recoiling loading tray or so-called shift tongue located with its forward end facing the breech ring but spaced from the rear end of the breech ring, when the barrel and the breech ring are in their fully run-out position, by a distance larger than the recoil length so that the barrel and the breech ring can recoil without being stopped by the nonrecoiling loading tray. An automatic gun of the type to which the invention is related is further provided with a breech block, which can be moved in the breech ring in a direction substantially perpendicular to the longitudinal direction of the barrel between a closed position and an open position by swingable control levers mounted on a control shaft journalled in the breech ring. This control shaft is arranged to be actuated by a non-recoiling cam path during the recoil movement after the firing of a round in such a way that the breech block is opened. When the breech block is opened, extractor means mounted at the front surface of the breech block will engage the flange on the empty case present in the firing chamber and impart a considerably larger velocity than the recoil velocity to the empty case, whereby this is ejected from the chamber through the loading channel of the breech ring. The non-recoiling loading tray may preferably be of the type known as a shift tongue, which is pivotal about a stationary shaft in the breech casing between a lower position, in which the upper side of the shift tongue can serve as a ramming path during the ramming of a round into the chamber, and a raised position, in which the lower side of the shift tongue can serve as a guide path for an empty case being ejected from the chamber during the recoil movement of the barrel and the breech ring.

To make it possible to unload or remove a live, that is not fired, round lying in the chamber an automatic gun of the type described has been provided with an unloading mechanism comprising operating means, generally manual operating means, for opening the breech block with the barrel and the breech ring in their fully run-out position. When the breech block is opened for the unloading of a live round lying in the chamber the extractor means on the breech block will engage the flange of the casing of the live round lying in the chamber, whereby this round is loosened in the chamber so that the round will silde out from the chamber through the loading channel of the breech ring by its own Weight, provided that the barrel is somewhat elevated. The intention is that the round shall by itself slide out onto the shift tongue, which is in its lower ramming position during the unloading process, so that the unloaded round can be removed from the shift tongue by the gun crew. When the barrel and the breech ring are in their fully run-out position during the unloading operation there is, however, as mentioned above, a gap between the rear end of the breech ring and the forward end of the shift tongue at least corresponding to the length of the recoil. As the round is tapered towards the point of the projectile, the rounds sliding out from the chamber through the loading channel of the breech ring will not move in an entirely straight line but the rear end of the round will have a tendency to sink down SC that the base of the case of the round strikes the forwarc' end of the shift tongue. Due to this the unloaded rounC will not automatically slide out onto the shift tongue as intended. There is also the risk that the case bottom o1 the round and the forward end of the shift tongue are damaged by the impact between the case bottom and the shift tongue. There is also a certain danger that the primer-cup of the round might be hit by the forward end of the shift tongue in such a Way that the round is fired, which would cause a very serious accident.

The principal object of the present invention is therefore to provide an improvement of an unloading mechanism of the type described above for an automatic gun having a non-recoiling loading tray, whereby the abovementioned disadvantages are eliminated.

The unloading mechanism according to the invention is characterized in that it comprises a guide member, which is moveable by the operating means for the opening of the breech block with the barrel and the breech ring in their fully run-out position between an inactive position, in which the guide member is located below the path of movement of the breech ring during the recoil, and an active position, when said operating means are actuated to open the breech block, in which active position the guide member is located between the breech ring and the forward end of the loading tray to form a guide path for a round sliding out through the loading channel of the breech ring in such a way that the guide member will guide the rear end of the round up onto the loading tray, whereby the round will automatically slide out onto the loading tray in the intended manner without striking the forward end of the loading tray.

In the following the invention will be further described with reference to the accompanying drawing, in which FIG. 1 shows schematically the rear portion of the barrel, the breech ring, the loading tray or shift tongue and the unloading mechanism of an anti-aircraft gun in perspective from the rear and with certain parts illustrated transparent, the unloading mechanism being in the position occupied at the beginning of the opening of the breech block for the unloading of a live round present in the firing chamber,

FIG. 2 is a corresponding view showing the unloading mechanism in the position occupied by it, when the breech block is fully opened and the round is on its way out of the chamber, and

FIG. 3 shows a detail of the unloading mechanism, viz. a spring casing connected to the operating shaft of the breech block and those members of the unloading mechanism coacting with this spring casing; seen from the opposite side of the breech ring as compared with FIGS. 1 and 2.

For the sake of simplicity and clarity the non-recoiling breech casing surrounding the breech ring, the loading tray and the unloading mechanism are not shown in the drawing. In the following description it will, however, be carefully pointed out, which parts are attached to this breech casing and consequently do not participate in the recoil movement.

FIG. 1 shows the rear end of the barrel 1 of the gun and the breech ring 2 with a live, not fired round 3 lying in the chamber. A non-recoiling loading tray 4 or shift tongue disposed to the rear of the barrel is pivotal about a shaft 5 stationary in the breech casing, not shown in the drawing, between the lower position shown in FIG. 1 and the position shown in FIG. 2, in which the upper side of the shift tongue can serve as a ramming path for a round during the ramming of the round into the chamber, and an upper somewhat raised position, in which the lower side of the shift tongue can serve as a guide path for an empty case being ejected from the chamber through the loading channel of the breech ring during the recoil movement of the barrel and the breech ring. The breech ring 2 is in a conventional manner provided with a recess 6 perpendicular to the longitudinal direction of the barrel. A breech block 7 is movable within this recess between the closed position shown in FIG. 1 and an open position shown in FIG. 2. The breech block 7 can be moved to its open position by two pivotal control levers 8 provided at their outer ends with operating lugs 9 engaging cam slots 10 in the opposite side surfaces of the breech block 7. The control levers 8 are mounted on a sleeve 11 mounted on a control shaft 12 provided with splines. The control shaft 12 is journalled in the breech ring 2 in any suitable manner not shown in the drawing. Both ends of the control shaft 12 protrude from the breech ring 2 at opposite sides thereof. At the right-hand side of the breech ring 2 there is a cylindric spring casing 13 consisting of a bottom 14 and a cover 15, which are mutually rotatable. Within the spring casing there is a spiral spring not shown in the drawing acting between the bottom 14 and the cover 15 of the spring casing. The bottom 14 of the spring casing is mounted on the breech ring 2, whereas the cover 15 of the spring casing is attached to the outer end of the control shaft 12. The opposite left-hand end of the control shaft 12 is in a manner that is conventional and therefore not shown in the drawing provided with a cocking lever located outside the breech ring 2. This cocking lever is coacting with a non-recoiling cam path in the breech casing during the recoil movement of the breech ring and the barrel after the firing of a round in such a way that the control shaft 12 is rotated in a counter-clockwise direction in the drawing during the recoil movement, whereby the control levers 8 will open the breech block 7. During this rotation of the control shaft 12 the spiral spring in the spring casing 13 will be wound so that the breech block 7 can be closed by this spring during the subsequent recuperation movement of the barrel 1 and the breech ring 2. During normal, very rapid opening of the breech block 7 during the recoil movement of the gun the extractor means mounted on the front surface of the breech block but not visible in the drawing will engage the flange of the empty case of the just fired round lying in the chamber, whereby a great velocity is imparted to the empty case which is ejected from the chamber through the loading channel of the breech ring.

To make it possible to open the breech block 7 with the breech ring in its fully run-out position for the unloading of a live round lying in the chamber the gun is provided with a special unloading mechanism. This mechanism comprises a forward cocking lever 16 pivotal about a shaft 17 stationary in the breech casing. The shaft 17 for the cocking lever 16 is so located in the breech casing that it is coaxial with the operating shaft 12, when the breech ring is in its fully run-out position. The forward cocking lever 16 is coupled to the forward end of a link 18 by suitable and conventional means such as a slot 16a in lever 16 and-a pivot pin 32 as can best be seen in FIG. 3, the rear end of link 18 being provided with a hook coacting with a rear cocking lever 19 on a shaft 20, which is journalled in the breech casing and is perpendicular to the longitudinal direction of the barrel. The shaft 20 is attached to a toothed segment 21 engaged by a pinion 22. The pinion can be rotated manually from the outside of the breech casing by means of a manually operable crank 23. When unloading a live round lying in the chamber, the barrel of the gun is elevated somewhat, whereafter the crank 23 is rotated in the counter-clockwise direction in the drawing, as indicated by the arrow 24 in FIG. 1. The shaft 20 and the rear cocking lever 19 will then be rotated in the clockwise direction in the drawing, as indicated by arrow 25 in FIG. 1, whereby the link 18 is moved to the right in the drawing and will rotate the forward cocking lever 16 in the counter-clockwise direction about the shaft 17. The outer end of the forward cocking lever 16 will then, as most clearly seen from FIG. 3, engage an engagement lug 26 on the cover 15 of the spring casing 13, whereby the cover 15 is rotated together with the operating shaft 12 in the counterclockwise direction in the drawing so that the breech block 7 is moved to its open position. At the same time the spring in the spring casing 13 is being wound in the same way as when the breech block 17 is opened in the normal man-ner during a recoil movement. The extractor means on the front surface of the breech block 7 will then act against the case flange of the live round lying in the chamber so that this round is loosened in the chamber, whereby the round, due to the somewhat elevated position of the barrel, will slide by its own weight out of the chamber through the loading channel of the breech ring.

According to the invention the unloading mechanism comprises a comparatively short guide plate 27 attached to the free end of an arm 28 mounted on a shaft 29, which is journalled in the breech casing and disposed perpendicular to the longitudinal direction of the barrel. The shaft 29 is provided with a second arm 30, the free end of which coacts with an engagement lug 31 on the link 18. In the inactive position of the unloading mechanism shown in FIG. 1 the guide plate 27 is disposed below the path of the breech ring during the recoil movement and is consequently not obstructing the recoil movement of the breech ring. When the breech block 7 is opened by means of the unloading mechanism in the manner described above, for the unloading of a live round lying in the chamber, the lug 31 on the link rod 18 will rotate the arm 30 together with the shaft 29 in the clockwise direction in the drawing, whereby the guide plate 27 will be swung from the inactive position shown in FIG. 1 to its working position shown in FIG. 2, which it reaches, when the breech block is completely opened. In this position the guide plate 27 will, as seen in FIG. 2, lie immediately in front of the forward end of the shift tongue 4 and extend from the shift tongue somewhat obliquely downwards and forwards towards the breech ring 2, whereby the guide plate 27 will guide the rear end of the round 3 sliding out through the loading channel of the breech ring up onto the shift tongue 4 so that the round will automatically slide out onto the shift tongue without striking the forward end of the shift tongue.

When the unloaded round has slid entirely out onto the shift tongue 4, the breech block 7 can be reclosed by rotation of the crank 23 in the clockwise direction in the drawing, whereby the forward cocking lever 16 is rotated in clockwise direction in the drawing about the shaft 17 and consequently releases the lug 26 on the cover 15 of the spring casing. The operating shaft 12 will then be rotated in the clockwise direction by the compressed spring in the spring casing 13 so that the breech block 7 is moved to its closed position by the operating levers 8. The shaft 29 for the guide plate 27 is also springloaded in some suitable manner not shown in detail in the drawing so that the guide plate 27 is returned to its inactive position shown in FIG. 1, when the breech block 7 is closed.

What is claimed is:

1. An automatic gun having a recoiling barrel with a breech ring attached to the rear end of the barrel, a firing chamber in the rear end of the barrel and in the breech ring, a breech block movable in said breech ring between a closed position closing said firing chamber and an open position, a breech block operating mechanism for opening and closing said breech block in response to a recoil movement and recuperation movement respectively of said barrel and breech ring, a non-recoiling loading tray disposed rearward of said breech ring and with its forward end spaced from said breech ring when the barrel and the breech ring are in the fully run-out position by a distance exceeding the length of the recoil movement of the barrel and the breech ring, wherein the improvement comprises an unloading mechanism for unloading a live round from said firing chamber with the barrel and the breech ring in the fully run-out position and the barrel somewhat elevated, said unloading mechanism including manual control means for opening and closing the breech block; first coupling means operatively connecting said manual control means to said breech block operating mechanism when the barrel and the breech ring are in the fully run-out position, whereby the breech block can be opened by actuation of said manual control means when the barrel and the breech ring are in the fully run-out position; a guide member movable between an inactive position in which said guide member is located outside the path of movement of said br ech ring during the recoil and recuperation movement, and an active position in which said guide member is interposed between said breech ring and the forward end of the loading tray so as to form a guide path for a live round sliding out of the firing chamber through said breech ring; second coupling means connecting the guide member to the manual control means for moving said guide member from the inactive position to the active position upon actuation of said manual control means for opening said breech block and for returning said guide member to the inactive position upon actuation of said manual control means for closing said breech block.

2. An automatic gun as claimed in claim 1, Where. said guide member when in said active position is locate immediately in front of the forward end of said loadir tray and extends in reference to the loading tr: downwardly and forwardly towards said breech rir whereby said guide member in said active position guidt the rear end of a live round sliding out of said breec ring up onto said loading tray.

3. An automatic gun as claimed in claim 1, wherei said guide member is secured to one end of an arm havir its opposite end secured to a non-recoiling rotatable shat said shaft being disposed perpendicular to the longitudin: direction of the barrel and being coupled to said manu: control means, actuation of said manual control meat rotating said shaft for pivoting said arm to swing sai guide member between the inactive position outside sai path of movement of said breech ring and the active pos tion interposed between said breech ring and the forwar end of sai-d loading tray.

References Cited by the Examiner FOREIGN PATENTS 711,189 9/1931 France.

BENJAMIN A. BORCHELT, Primary Examiner. S. C. BENTLEY, Assistant Examiner. 

1. AN AUTOMATIC GUN HAVING A RECOILING BARREL WITH A BREECH RING ATTACHED TO THE REAR END OF THE BARREL, A FIRING CHAMBER IN THE REAR END OF THE BARREL AND IN THE BREECH RING, A BREECH BLOCK MOVABLE IN SAID BREECH RING BETWEEN A CLOSED POSITION CLOSING SAID FIRING CHAMBER AND AN OPEN POSITION, A BREECH BLOCK OPERATING MECHANISM FOR OPENING AND CLOSING SAID BREECH BLOCK IN RESPONSE TO A RECOIL MOVEMENT AND RECUPERATION MOVEMENT RESPECTIVELY OF SAID BARREL AND BREECH RING, A NON-RECOILING LOADING TRAY DISPOSED REARWARD OF SAID BREECH RING AND WITH ITS FORWARD END SPACED FROM SAID BREECH RING WHEN THE BARREL AND THE BREECH RING ARE IN THE FULLY RUN-OUT POSITION BY A DISTANCE EXCEEDING THE LENGTH OF THE RECOIL MOVEMENT OF THE BARREL AND THE BREECH RING, WHEREIN THE IMPROVEMENT COMPRISES AN UNLOADING MECHANISM FOR UNLOADING A LIVE ROUND FROM SAID FIRING CHAMBER WITH THE BARREL AND THE BREECH RING IN THE FULLY RUN-OUT POSITION AND THE BARREL SOMEWHAT ELEVATED, SAID UNLOADING MECHANISM INCLUDING MANUAL CONTROL MEANS FOR OPENING AND CLOSING THE BREECH BLOCK; FIRST COUPLING MEANS OPERATIVELY CONNECTING SAID MANUAL CONTROL MEANS TO SAID BREECH BLOCK OPERATING MECHANISM WHEN THE BARREL AND THE BREECH RING ARE IN THE FULLY RUN-OUT POSITION, WHEREBY THE BREECH BLOCK CAN BE OPENED BY ACTUATION OF SAID MANUAL CONTROL MEANS WHEN THE BARREL AND THE BREECH RING ARE IN THE FULLY RUN-OUT POSITION; A GUIDE MEMBER MOVABLE BETWEEN AN INACTIVE POSITION IN WHICH SAID GUIDE MEMBER IS LOCATED OUTSIDE THE PATH OF MOVEMENT OF SAID BREECH RING DURING THE RECOIL AND RECUPERATION MOVEMENT, AND AN ACTIVE POSITION IN WHICH SAID GUIDE MEMBER IS INTERPOSED BETWEEN SAID BREECH RING AND THE FORWARD END OF THE LOADING TRAY SO AS TO FORM A GUIDE PATH FOR A LIVE ROUND SLIDING ONE COUPLING MEANS CONNECTING THE GUIDE MEMBER TO THE OND COUPLING MEANS CONNECTING THE GUIDE MEMBER TO THE MANUAL CONTROL MEANS FOR MOVING SAID GUIDE MEMBER FROM THE INACTIVE POSITION TO THE ACTIVE POSITION UPON ACTUATION OF SAID MANUAL CONTROL MEANS FOR OPENING SAID BREECH BLOCK AND FOR RETURNING SAID GUIDE MEMBER TO THE INACTIVE POSITION UPON ACTUATION OF SAID MANUAL CONTROL MEANS FOR CLOSING SAID BREECH BLOCK. 